Saying it could work for casual queue misses the fact that newcomers will queue for casual and they will literally quit the game mode immediately if they keep being stomped by premades. There's a reason people say FL sucks even though it's an incredibly fun game mode: newcomers don't really have anywhere to properly get the hang of how PVP plays differently.

Even queue syncing can ruin the fun if there's even just two people on a team working together. Valence's idea of making sure there is a duo on each team could work, but honestly it'd probably be better if they put a system in place to PREVENT people from being on the same time more than one or two matches in a row.